Three-piece spring locking slider



Dec. 18, 1962 o. FIRING THREE-PIECE SPRING LOCKING SLIDER Filed Oct. 27. 1960 United rates Patent 3,fi8,542 Patented Dec. 18, 1962 Free 3,068,542 THREE-PIECE SPRING LOCKLNG SLlDER Osborne Firing, Woodbury, Conn., assignor to Scovill Manufacturing Company, Waterbury, Conn, a corporation of Connecticut Filed Oct. 27, 1960, Ser. No. 65,359 Claims. (Cl. 24-20514) My invention relates to locking sliders for zipper fasteners and more particularly to an improved three-piece spring locking slider.

Prior spring locking sliders for zipper fasteners of this general type have required a complicated spring which has been difficult in the first place to manufacture. Also, in sliders of this type which have heretofore come to my attention, a difficult operation has been required either in deforming portions of the slider body metal or portions of the spring itself in order to anchor the locking member in place.

An object of my invention is to provide an improved three-piece spring locking slider in which the locking member may be assembled and held in place without any such deforming of the spring or slider body.

Another object is to provide a less costly spring which can be bent up readily from fiat strip metal. A further object is to provide a one-piece locking spring member which is compact and which at the same time has a comparatively long flexible section so as to improve the spring action and add to the life of the spring. Other objects and advantages will hereinafter more fully appear.

In the accompanying drawing, I have shown for the purpose of illustration, one embodiment which the invention may assume in practice.

In the drawing:

FIG. 1 is a perspective view of my improved locking slider;

FIG. 2 is a plan view of the same;

FIG. 3 is a longitudinal central cross-section showing the locking member in locked position;

PEG. 4 is a similar cross-section showing the locking member in unlocked position;

FIG. 5 is a perspective view of the spring locking member itself; and,

FIG. 6 illustrates the pull tab before assembly with the slider.

The three pieces which make up the slider are the slider body, generally designated 7, the spring locking member, generally designated 3, and the pull tab 9.

The slider body comprises front and back Wings 10 and 11 joined together at one end by a neck 12 and having the usual side flanges 13 to define a Y-shaped channel for passage of the zipper fastener elements in the well known manner. The narrow end of the slider may be described as having an open mouth 14. The front wing of the slider has a longitudinally-extending centrally arranged opening 15, and a pair of upstanding lugs are integral with the front wing, the one adjacent the neck being designated 16 and the other adjacent the mouth being designated 17. These lugs are struck up from the material of the front Wing in forming the opening and project partially over this opening at each end.

The spring locking member 8 which is positioned in the opening 15 consists of a single piece of fiat strip metal having a U-bend 18 at one end fulcruming under the lug 16 which is the one nearest the neck of the slider. Extending from the U-bend is the long inner arm 19 which preferably has an elongated central opening 20 extending the major length of said arm and through the U-bend 18 to increase its flexibility. This inner arm has a reduced extension 21 at its front end bearing against an inner surface of the front wing adjacent the mouth of the slider,

and preferably, this extension 21 fits into a recess 22, which recess extends from the mouth 14 to the opening 15. The outer arm 23 of the member 8 has a central portion which is bent outwardly to form an open-sided loop 24 which extends outwardly into the space between the lugs 16 and 17 so that such lugs limit the movement of the locking member in an endwise direction. At the free end of the outer arm 13 on one side thereof is an inwardly projecting locking prong 25' which may be somewhat tapered and it will be noted that the end portion of the inner arm has a cut-out 26 to accommodate the backand-forth movement of the locking prong into and out of the slider channel.

The pull tab 9 is a flat metal plate bifurcated at one end to provide the arms 27 and 28 and from the ends of these arms, there extend toward each other the trunnions 29. These trunnions are of generally oval or elongated cross-section with the maximum dimension extending in the plane of the pull tab. In this Way, as seen in FIG. 3, in the normal locking position, the trunnions extend into and substantially fill up the opening in the loop 24 of the locking member 8. However, when the pull tab 9 is lifted, as seen in FIG. 4, the trunnions 2.9 will cam against the inner surface of the loop 24 and lift the locking prong 25 out of the slider channel against the resistance of the spring member, which is confined at the U-shaped fulcrum end 13 by the lug 16 and at the other end by the end of the inner arm bearing against the inner surface of the recess 22.

One of the features of construction which may be mentioned is that while the neck 12 of the slider is of generally V-shaped cross-section, it has a solid top portion 3% to provide additional strength to compensate for the weakening of the front wing of the slider in the forming of the opening 15 and lugs 16 and 17.

Inasmuch as the overall height of the spring member 8 is greater than the height of the slider open mouth 14, it is necessary to provide suitable clearance spaces in the slider body to assist in the assembly of the spring member. For this purpose, the upper inner surface of the back wing 11 is provided with a pair of spaced parallel longitudinal grooves 31 and 32 through which the divided portion of the spring arm (by reason of the central opening 29) may freely pass, such as shown in dotted outline in FIG. 4. Also, the front end of the slider wing 11 adjacent the groove 32 is beveled as at 33 as a clearance for the locking prong 25.

In order to assemble the three pieces of my improved locking slider, it is only necessary to insert the locking member 8 endwise into the mouth 14 of the slider and move it upwardly until it rests in the opening 15 with the loop 24 fitted between the lugs 16 and 17. Then the pull tab which is formed with the arms some-What spread apart, is placed in position and the arms bent together to engage the trunnions =29 into the opening of the loop 2'4.

To assist in assembling the trunnions 29 into the spring loop 24, the terminal ends of said trunnions are biased as indicated at 29a in FIG. 9 and also, the forward edges are beveled as indicated at 2%. This beveling formation of the trunnions will permit their telescopic insertion into the spring loop 24 without danger of abutting or jamming against the edges of the spring member 8.

Although it is not essential, the spring in this assembled position, shown in FIG. 3, may be under slight tension. At any rate, the parts are all held together firmly by this one assembly operation. When assembled under tension, the outer arm of the spring member may be sprung outwardly by a suitable tool applying upward pressure on the locking prong 25.

It may also be added that the lug 17, in addition to spas-54.2

buttressing the locking member against endwise movement, serves as a positive step to prevent undue bending of the spring in the event of any excessive force applied to the pull tab.

As a result of my invention, it will be observed that in contrast to other attempts to produce three-piece spring locking sliders, the slider of my invention has an improved action and a more durable spring element due to the effective length of the springy portions. Also, my improved slider does not require a spring that in itself is unduly complicated, or any difiicult bending operations during assembly.

What I claim is:

l. A three-piece spring locking slider'for zippers comprising :front and back wings united by a neck at one end and being spaced apart to provide an open mouth at the other end, said wings and neck defining a Y-shaped channel for passage of the zipper fastener elements, said front wing having a longitudinally extending opening therein, a pair of upstanding lugs integral with said front wing, one projecting over each end of said opening, a spring locking member positioned in said opening, said locking member consisting of a single piece of flat strip metal having a U-bend at one end to provide an outer and inner arm,v said U-bend fulcrurning under that one of said lugs nearest the neck of the slider, the central portion of the outer arm be ing bent outwardly to form an open-sided loop between the ends of said lugs, the free end of said outer arm having an inwardly extending locking prong adapted to project into the slider channel, said inner arm constituting a springy extension, the free end of which engages an inner surface of said front wing adjacent the mouth of the slider but without being attached thereto, and a bifurcated pull tab having inwardly extending trunnions projecting into said loop of the locking member by which means said 4- slider body, spring locking member and pull tab are held in assembled position.

2. A locking slider for zippers as defined in claim 1 wherein said trunnions have an elongated cross-section with the major dimension extending in the plane of the pull tab whereby the outer arm of said locking member may be sprung outwardly when the pull tab is lifted toward a vertical position with respect to the slider body so as to unlock the slider by lifting the locking prong out of the slider channel.

3. A locking slider for zippers as defined in claim 1 wherein the inner arm of the locking member has a longitudinally extending opening to increase its flexibility.

4. A locking slider for zippers as defined in claim 1 wherein the front wing of the slider has an internal recess leading from said open mouth of slider to said opening in the front wing or" the slider to increase the depth of said open mouth and wherein the over-ail thickness of the U- bent locking member is no greater than the depth of such month to permit the locking member to be inserted endwise through said open mouth whereby it may be moved outwardly into said opening.

5. A locking slider for zippers as defined in claim I wherein the front wing of the slider has an internal recess adjacent its open mouth and the free end of the inner arm of the locking member engages in said recess, and wherein said inner arm has a cut-out to accommodate the inwardly projecting locking prong.

Reerencesited in the file of this patent UNITED STATES PATENTS 

